Honeycomb materials



June 15, 19,65 D. D. WHITE HONEYCOMB MATERIALS 2 Sheets-Sheet 1 Filed Oct. 19, 1961 DES/"0ND BEVEREZWME f A llorneys June 15, 1965 D. D. WHITE noumcowa MATERIALS 2 Sheets-Sheet 2 Filed Oct. 19. 1961 DESMOND DEVL'RELL'WfiiT/E a Attorney-9 United States Patent 0 3,139,501 HGNEYCQMB MATERIALS Desmond Deverell White, Radlett, England, assignor to Dufayiite Developments limited Filed Get. 19, 1961, Ser. No. 145,286 Qlaims priority, application Great Britain, Get. 21, 1969, 36,226/60 2 Claims. (ill. 156-189) The present invention relates to structural honeycomb material.

Gne method of producing unexpanded honeycomb materlai from sheet involves indin g the sheet material in the form of two webs, one at least of which is tensioned, one

upon the other around a rotary former whilst applying an adhesive to the material of the webs, in such a manner that the layers accumulated on the former have the adhesive arranged along bands on both of their sides, the hands on the one side hei g in staggered relationship with the bands on the other side, and continuing to wind the webs upon the former until a useful number of layers has been accumulated. Subsequently the wound material is removed from the former and cut into slices for expan sion to yield a core material for double skin structures.

The apparatus employed includes a rotary former, means for feeding a pair of continuous webs of the sheet material, at least one of which is tensioned to the former in such a manner that as the former is rotated the webs are wound together thereon and at least one printing I device for applying adhesive to the material in positions such that the wound mat rial the adhesive is distributed such that each layer has the bands on one side thereof staggered with reference to the bands on the other side thereof.

it is an object of the present invention to provide the method and the apparatus in such modified forms that the sheet material may be used in the form of one or other odd number of webs, that is to say a single web wound alone or together with an even number of other webs.

in accordance with the present invention there is provided a method of producing unexpanded structural honeycomb material by winding sheet material upon a rotary former and applying to the sheet material, during the windoperation, an adhesive which is distributed in bands positioned such that the material accumulated on the former is, when sliced, expandable to the cellular state, charact rised in that the sheet material consists of one web thereof which is wound on the former alone or together with an even number of other webs, whilst adhesive is applied to the web or webs in hands by gluing apparatus adapted and arranged to locate the bands such that the bands on any layer of the accumulated material which is derived from the web, or any one web as the case may be, are staggered with respect to the bands on the next preceding layer so derived.

Further in accordance with the present invention there is provided apparatus for producing structural honeycomb material by winding sheet material on a rotary former characterised by means for supplying the sheet material to the former in the form of a single web, with or without an even number of other webs, and gluing apparatus operable to print bands of adhesive on the web or webs, during the winding thereof, in positions such that the bands on any layer of the accumulated material which is derived from the web or any one web as the case may be, are staggered with respect to the bands on the next preceding layer so derived.

As the principles of the invention may be clearly understood from a consideration of the simple and preferred case where only one web is employed, the folmasses lowing description will be confined to that simple case. It win be appreciated that the employment of additional webs (e.g. a total of three webs) merely involves the provision of additional Web handling means and the multiplication of the printing devices.

in a convenient form of the method the adhesive is applied to the web by a printing roller which is movable axially between two positions related such that the bands applied in the first position are staggered in the wound material relative to the bands applied in the second position, said roller being reciprocated between the two positions in synchronism with the rotation of the former. in an alternative arrangement there is used a pair of printing rollers which are brought into their printing positions alternately to give the same effect. 7

Conveniently the printing roller is mounted to apply the adhesive to said web at a position where said web has been received upon the former.

This arrangement ensures automatically that the bands of adhesive are correctly positioned relative to the former itself and consequently relative to one another. The adhesive may however be applied to the web as'it approaches the former if preferred. In order to minimise cutting losses, the change from bands in one position relative to the former to bands in the staggered position should always occur at the same angular position of the former, e.g. at a corner thereof when a polygonal former or other former having planar faces is employed, and should take place over as short a distance as possible.

A single change per revolution is all that is necessary, though any other convenient odd number of changes, e.g. at alternate corners of a hexagonal former or at each corner of a pentagonal one, may be provided at the cost of increased complexity.

The employment of a single web, rather than another odd number of webs is preferred since it requires a gluing apparatus of relatively simple type. Additionally, it avoids the need to provide for the handling of more than one web; this is an important consider tion in practice because the rolls in which the material is supplied tend to be very heavy and to require very robust supports and every web usually requires a set of guide rollers as part of its feeding arrangement. Furthermore, for some applications the web material requires to be treated with an impregnating agent, for example a thermosettable resin or a flame proofing agent before being formed into honeycomb. Such treatment has hitherto been carried out in a preliminary operation, but the employment of a single web in accordance with this invention makes it practicable to carry out the treatment and the production of the unexpanded honeycomb in a single continuous operation. To carry out the treatment of a plurality of webs simultaneously, though obviously possible, would necessitate such a duplication of treatment equipment as to render the practice uneconomic.

The following description of preferred embodiments of the method and apparatus in which description reference is made to the accompanying drawing is given in order to illustrate the invention.

In the drawing:

FIGURE 1 shows one embodiment ot the apparatus 3 running in the direction of the web, there is provided a printing head having a printing roller 9 supplied from a reservoir 11 via an intermediate roller. The printing head is carried by-a spring loaded linkage 12, 13, 13 suspended from a carriage 14 mounted for. motionin a direction parallel with the axle 6 upon rails 17.

A cam-plate 22 having a pair of diametrically opposed, oppositely inclined cam surfaces, which is geared to the axle 6 for rotation at half the'speed of the drum is engaged at its periphery by pins 25 carried by an arm 27 keyed to a vertical axle 28. A second arm 29 keyed to brought into engagement with the pins 25 on alternate,

revolutions of the drum 3.

Accordingly the adhesive bands printed during any revolution are staggered relative to those printed during 1 v the preceding revolution and the accumulated material can be expanded to the cellular state after removal fromthe drum followed by slicing parallel with the axle 6.

i the material whilst it is exposed on and supported by the drum, such difficulties as may arise from the weakening of. the 'material on its being wetted with adhesive whilst under tension are avoided.

In the embodiment of the apparatus shown. in FIG- URE 3 there is provided between the supply roll 1, and a hexagonal drum (like the drum 3 but not shownin this figure) a resinating trough 32, a drying chamber 33 and an axially movable printing head 34. The sheet material drawnfrorn the roll 1 is impregnated with a solution of a thermosetting resin in the trough 32 and subsequently dried in the chamber 33 to convert. the resin to the solid but still curable state'by a current of hot air which leaves "together with entrained solvent vapours at outlet 36.

The dried material then passes through the printing head 34 which is automatically moved from one extreme position to the other by a pneumatic ram (not shown) actuated by a trip on the drum itself. As the material is the next always corresponds "with acorner. The direction of rotation ofthe drum is anti-clockwise.-

It will be understood that various departures may be made from the embodiment just described without departing from thescope of the invention. For example the printing roller may be of a form such as to apply the bandsacross .the direction of the Web, i .e. parallel with the axle of the former or the apparatus may be constructed with a spring loaded or counter-balanced pressure roller; or a system of tensioned belts operating on the underside of the druminstead of or in addition to theroller '7. p t

I claim: V p a 1. A method of producing unexpanded structural honeycomb material whichcomprises winding a single web of sheet material upon a rotary former formed, with flat web receiving faces, applying to the sheet material, during the winding operation, an adhesive which is'distributed in mutually parallel evenly spaced bands extending in the winding direction of the ,web'material, shifting the posi tion of the bands across the web between a'firstregistraw tion position'and a second registration position an [odd number of times for each revolution of the former, said I shiftings being made when the former occupies predetermined angular positions on its rotation and said first and second positions being such that on account of the shifting the wound material has the adhesive bands on one layer staggered with respect to the adhesive bands on the next preceding layer, slicing thewound material parallel with the axis of rotation of'the former to divide it into sections and removing the secti'ons'from the former.

2. A method according to claim 1 in which the adhesive is applied to the web at arposition where said web has been received upon the former and the shifting between the first and second registration positions,

7 References ited by the Examiner I V UNITED STATES PATENTS EARL M. B RGERT, Primary Examiner. 

1. A METHOD OF PRODUCING UNEXPANDED STRUCTURAL HONEYCOMB MATERIAL WHICH COMPRISES WINDING A SINGLE WEB OF SHEET MATERIAL UPON A ROTARY FORMER FORMED WITH FLAT WEB RECEIVING FACES, APPLYING TO THE SHEET MATERIAL, DURING THE WINDING OPERATION, AN ADHESIVE IS DISTRIBUTED IN MUTUALLY PARALLEL EVENLY SPACED BANDS EXTENDING IN THE WINDING DIRECTION OF THE WEB MATERIAL, SHIFTING THE POSITION OF THE BANDS ACROSS THE WEB BETWEEN A FIRST REGISTRATION POSITION AND A SECOND REGISTRATION POSITION AN ODD NUMBER OF TIMES FOR EACH REVOLUTION OF THE FORMER, SAID SHIFTING BEING MADE WHEN THE FORMER OCCUPIES PREDETER- 